hard to say without seeing it or knowing what size pipes you have, you will need to have a system that will deliver enough gas to the range with all burners on and still adequately supply your other gas needs too.

You really need to get a qualified plumber or gas fitter to look and advise you.

You can check out the necessary specs for various ranges on the mfgs' websites. Then do what antss suggests and have a plumber come out to check your home and advise you if anything's needed.

On a small range you can get by with 3/8" supply line. My Monogram dual fuel (just 4 burners and a grill on gas) specified a 1/2" line. IIRC, I think some 48" ranges with 2 ovens want even larger.
Casey

1/2" ID is all you will need. No ranges require anymore than that, at least in residential ranges(viking/wolf/thermador etc).

I would do lots of homework on the range, Viking & DCS should not be your first choices(viking for reliability, DCS because it may be sold or non existant in the next year or so)

From the Bluestar installation guide-

"The gas supply line must be the same size
or larger than the gas inlet of the appliance.
Your appliance has either a ½"
NPT or ¾" NPT gas inlet connection. We
recommend the supply line be ¼" NPT
larger than the gas inlet of the appliance."

>>DCS because it may be sold or non existant in the next year or so

joboxes - could you elaborate on this - DCS is currently owned by F&P - are they planning to sell it or close it down?

Well last I heard F&P's stock price and cash flow was so poor they were looking for a large bailout from the NZ government. If that's the case and they go bankrupt as Chrysler and GM chances are that they would look for way to move DCS or some other part of the company to stay liquid.

Haier is buying 17% of F&P...I don't think they looking for bankruptcy solution...
http://investing.businessweek.com/research/stocks/transactions/transactions.asp?ric=FPA.NZ

i believe it depends on the gas pressure that you get. it should be on your gas bill or you can call the gas co. and get that info.
john

The final fitting on almost all pro residential ranges is 1/2" as mentioned by several others. The supply line itself may need to be larger if the run is a longer distance or if there are other appliances sharing the line. Always try to take the supply from a larger source like the gas meter or furnace area. Always use a qualified gas professional who follows local gas codes.

pressure is only a very small part of the equation. With big gas hogs like on demand water heaters, furnaces, and pro ranges the more salient things to look at are volume and distance from the meter. You then can size your lines correctly based on that. Pressure is fairly constant, but volume fluxes widely depending on what you are running. At one of my places I can have nearly 1,000,000 BTUs of demand at once and that's how the system is designed. Now, it has a rangetop, 2 large demand water heaters, a big BBQ, and 2 gas log sets. It's very unlikely to run all together but you don't want to get a cold shower because someone want to grill a burger at the same time 2 fires are going. This make the supply pipe from the LP tank almost as big as your arm.